Question

5050 people are randomly selected and the accuracy of their wristwatches is checked, with positive errors representing watches that are ahead of the correct time and negative errors representing watches that are behind the correct time. The 5050 values have a mean of 115115sec and a standard deviation of 177177sec. Use a 0.020.02 significance level to test the claim that the population of all watches has a mean of 00sec.

The test statistic is

The P-Value is

The final conclustion is

A. There is not sufficient evidence to warrant rejection of the claim that the mean is equal to 0
B. There is sufficient evidence to warrant rejection of the claim that the mean is equal to 0

Answer 1

This is the two tailed test .

The null and alternative hypothesis is

H₀ : = 0

H_a : 0

Test statistic = t

= ( - ) / s / n

= (115 - 0) / 177 / 50

Test statistic = 4.594

P-value = 0.000

B. There is sufficient evidence to warrant rejection of the claim that the mean is equal to 0